JPH0817259A - Flat cable branch connecting structure - Google Patents

Abstract

PURPOSE:To branch connecting structure in which flat cable is simply connected at low cost, a connecting space is decreased, an electricity carrying area and connecting pitch are not limited, and quality and durability are enhanced. CONSTITUTION:Insulating layer removed parts 6 are dottedly formed on insulated layers 4 of a main flat cable 1 and a branch flat cable 2, the cables are piled so as to cross each other, and cable conductors 3, 3 exposed to the removed parts 6 are made conductive with solder layers 5. By this construction, additional connecting parts are eliminated and work is automated. Since the removed parts 6 are formed so as to conform to the pitch of the conductor, limitation of connecting pitch is eliminated, and damage of the conductor 3 is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a branch connection structure of a flat cable which allows a flexible flat cable (FFC) to be easily and advantageously branched in various aspects.

[0002]

2. Description of the Related Art A flat cable capable of planar wiring tends to be widely used not only for wiring in electric machines and electronic devices but also for vehicle wiring as an alternative to conventional wire harnesses in which electric wires are bundled.

The flat cable used as a substitute for this wire harness is required to be connected in various forms such as terminal connection, intermediate connection, branch connection, cross connection and the like.
In order to make such a connection as simple as possible, for example, JP 63-13285 A proposes a crimping connection strip in which sharp teeth are pierced from the outside of the insulating layer to contact the cable conductor. There is.

[0004]

The connecting strip disclosed in the above publication is difficult to improve the work efficiency because the crimping work basically depends on the manpower.

Further, the cost of parts is high, and a lot of connection space is required. Further, the connection pitch is limited by the size of the connection strips, and the number of connection strips is required according to the number of connection conductors, which is disadvantageous in terms of circuit design or economically. In addition, since the conductive surface is only the strip penetrating surface, it is easy to be subject to usage restrictions due to the current carrying capacity.

An object of the present invention is to provide a branch connection structure for a flat cable which can solve these problems at once.

[0007]

DISCLOSURE OF THE INVENTION The branch connection structure of the present invention devised in order to solve the above-mentioned problems is a trunk flat cable in which a connecting portion of a conductor is exposed by removing an insulating layer in spots and a branch. The flat cables are crossed and overlapped, and the conductor exposed portions corresponding to the positions of these cables are soldered to be electrically conducted.

In another structure, the trunk flat cable and the branch flat cable, in which the insulating layer on the mating surface side is removed over the entire mating surface, are crossed with an anisotropic conductive sheet between them. The conductor exposed by the removal of the insulating layer is soldered to the conductive portion in the anisotropic conductive sheet existing only between the conductors of the connection partner so as to be electrically conducted.

Further, the structure in which the anisotropic conductive sheet is replaced with an insulating sheet having holes at positions corresponding to the conductive portions of the sheet and the conductors to be connected are soldered to each other at the holes are also described above. It will be an effective solution to the problem.

[0010]

[Function] The insulating paste is removed in spots, the solder paste is supplied on the exposed conductor with the existing dispenser, the other flat cable is overlaid and heated with a hot press machine,
The branch connection is completed when pressure is applied. This work can be automated, increasing work efficiency. Further, since a joint such as a connecting strip is not used, space is not required, the connecting cost can be kept low, and the connecting pitch is not limited.

Further, electrical continuity can be obtained in the entire conductor crossing portion, and a conductor having a large current-carrying capacity can be connected without any trouble.

In addition, since the conductor is not damaged as in the connection strip, quality and durability are improved.

The same effect can be said for a structure in which the insulating layer is peeled off over the entire mating surface and soldering is performed by interposing an anisotropic conductive sheet or a perforated insulating sheet between the cables.

[0014]

FIG. 1 shows a concrete example of the connection structure of the present invention. 1 and 2 of the drawings are flexible flat cables made by covering a flat cable conductor 3 with an insulating layer 4. These cables are often the same, but here the former is 1, to separate the trunk cable and the branch cable.
The latter was set to 2.

The core flat cable 1 has a top surface side insulating layer corresponding to each conductor, while the branch flat cable 2 has a bottom surface side insulating layer spot-removed (6 is a removed portion). A part (connection part) of is exposed. The insulating layer 4 is removed by irradiating a YAG laser, and the positions of the removed portions of both cables correspond to each other.

After completion of this pretreatment, solder paste is supplied onto the exposed conductors of the backbone flat cable 1 by a dispenser. Soldering is preferably performed using non-cleaning flux from the viewpoint of the quality of the joint and workability.

Next, the branch flat cable 2 is shown in FIG.
As shown by a chain line in (a), this overlapping portion is heated and pressed. As a result, the solder paste melts and adheres to the conductor of the connection partner, and the conductor 3 is electrically connected via the solder layer 5 as shown in FIG.

FIG. 2 shows an example in which the insulating layer 4 on the mating surface side is removed and joined over the entire area of the mating surface. In this case, if the insulating layer removing portion 7 of the branch flat cable 2 is directly overlapped on the insulating layer removing portion 7 of the backbone flat cable 1, the conductors to be insulated are short-circuited, so that the anisotropic conductive sheet 8 is interposed therebetween. . The anisotropic current-carrying sheet 8 is provided with a conductive portion 9 for flowing electricity from one surface side to the other surface side of the sheet only at a portion where the cable conductors of the connection partner intersect and overlap each other. In addition to the ones in which the conductive fibers are penetrated and flocked, and the ones in which the conductive material is penetrated and embedded, the insulating layer of the flexible printed circuit board and the flexible flat cable is spot-removed by the YAG laser to connect the conductors above the connection points. Those partially exposed on the lower surface can be preferably used.

FIG. 3 shows an insulating sheet interposed on the cable mating surface instead of the anisotropic conductive sheet. The insulating sheet 11 is, for example, a polyethylene terephthalate (PET) film having a thickness of about 50 μm with holes 12, and the conductors to be connected are soldered to each other at the holes 12.

It is preferable that these sheets 8 and 11 are bonded to the cable with an adhesive at the time of hot pressing because the connection can be stabilized.

[0021]

As described above, according to the present invention, the trunk flat cable and the branch flat cable are overlapped with each other so that only the conductors to be connected are non-insulated and the portion is directly soldered. Since electrical connection is made by attaching or soldering via the conductive portion of the anisotropic conductive sheet, efficiency can be improved by automation of work and a connection space can be reduced.

Further, since a joint such as a connecting strip is not used, the connecting cost does not increase and the connecting pitch is not limited.

Further, a sufficient conduction area can be secured to handle a large current, and the cable conductor is not damaged.
Therefore, quality and durability are also improved.

[Brief description of drawings]

FIG. 1A is an exploded perspective view showing an embodiment of the present invention, and FIG. 1B is a sectional view of a completed connection portion.

FIG. 2 is an exploded perspective view of another embodiment.

FIG. 3 is a perspective view of an insulating sheet used in place of the anisotropic conductive sheet of FIG.

[Explanation of symbols]

 1 Core Flat Cable 2 Branch Flat Cable 3 Cable Conductor 4 Insulating Layer 5 Solder Layer 6, 7 Insulating Layer Removal Section 8 Anisotropic Conductive Sheet 9 Conductive Section 10, 11 Insulating Sheet 12 Holes

Claims (3)

[Claims] 1. An exposed conductor in which a trunk flat cable and a branch flat cable in which a connecting portion of a conductor is exposed by spot-removing an insulating layer are crossed and overlapped, and the positions of these cables correspond to each other. Flat cable branch connection structure that solders each part to electrically connect. 2. A trunk flat cable and a branch flat cable in which an insulating layer on the mating surface side is removed over the entire mating surface are overlapped with an anisotropic conductive sheet between them to overlap each other, and The conductor exposed by the removal,
Branch connection structure of a flat cable that is electrically connected by soldering to a conductive part in an anisotropic conductive sheet that exists only between conductors of a connection partner. 3. The anisotropic conductive sheet according to claim 2 is replaced with an insulating sheet having holes formed at positions corresponding to the conductive portions of the sheet, and conductors to be connected are soldered to each other at the holes. Flat cable branch connection structure.